Plumb level



Sept. 28,1926. 1,601,439 f A. Y. HARPER PLUMB LEVEL Filed Sept. 10, 1925 Patented Sept. 28, 1926.

UNITED STATES 1,601,439 PATENT OFFICE.

ALFRED Y. HARPER, OF MONTREAL, QUEBEC, CANADA.

PLUME Application led September My invention relates to plumb levels oi" the mechanical kind in that the use ot spirits is avoided, and the object of the invention is to provide a mechanism which will register as required horizontal and vertical positions and in angular position. n

A iurther object of the invention is to eliminate all springs and obtain accurate indications of the level, perpendicularity and angular position of any surface or article to be constructed or which exists.

The invention also has for its object to provide a mechanical level the index of which is controlled solely by a counterY weight to be actuated with respect to and movable independently of the dial, for more delicate and correct indication of position.

To this end the invention may be said to consist in a case containing a dial graduated in degrees of a circle, the dial being arranged upon the face plate of the case, the back plate of which is permanently lixed in parallelism with the face plate by being made the bottom of a cylinder case or otherwise formed integrally with the frame in which the face plate and dial are mounted. A tine arbor is mounted at one end in a bearing in the back plate centrally thereof, and its opposite end protrudes centrally through the face plate and dial in which it finds bearing while the protruding end has an index hand mounted rigidly upon it.

Between the tace plate and back plate is mounted on the arbor a counterweight ot' peculiar form in thatit is of substantially the width of the interior of the case and is hung from the arbor to which it is rigidly connected by a goose neck for the purpose of giving full scope for the movement of t-he counterweight as the angular position vof the level is changed. y The level thus produced is extremely sensitive.

ForV full comprehension, however, of my invention, reference must be had to the accompanying drawings, in which similar reference characters indicate the same parts, and wherein:

Figure 1 is a face view of a plumb level constructed according to my invention;

Figure 2 is a transverse vertical sectional view taken on line 2 2 Figure 1,- and drawn to a larger scale tor clearness of illustra-V tion;

Figure 3 is a longitudinal sectional view taken on line 3 3 Figure 2; and

taken on line 4 4 Figure 2, illustrating` particularly the case for the mechanism ot my improved plumb level, and the manner in which it is mounted in the stock.

In the drawings the stock is indicated at 2; it has a cavity in the form of circular bore 3 in the center of one side thereof; the outer end ot this cavity or bore is enlarged to present a shoulder 4. The case for the mechanism is indicated 'at 5, back plate at 6, face plate at 7 and dial at 8. The fine arbor is indicated at 9 and counterweight at 10, `and the goose neck connection between the counterweight and arbor at 12, while the indexV handA is indicated at 14. The counterweight is formed with a sleeve 40 in which the arbor 9 is carried rigidly, its ends protruding to engage and bear in the backplate 6 and tore-plate 7 through which latter it protrudes through the dial and carries the index 14.

As shown in Figure 2 the counterweight is substantially'the full width of the interior of the case between the face plate and the back plate, the effect being that in the event of the level being jarred by being dropped, or otherwise, the counterweight will be sustained in position by the ends of the casing, and because of the close fit and relatively large form of the counterweight maximum freedom of movement is` provided by an opening 15 to the atmosphere. The case is held in place by three wood screws 30 passed through countersunk screw holes 31 and screwed into the stock ;V while the face plate is clamped in place by three machine screws 32 the heads of which overlap the edge of the tace plate, for the purpose.

The shoulder 4 is suiiiciently deep to accommodate an outwardly liared protecting plate 2O the outer rim of which is secured by,

screws 25 to the face ot the stock, while the l'reduced inner rim surrounds the dial. n E

My improvedv level possesses maximumV sensitiveness because of the particular form of the counterweight and its relatively large size, while the ends of the sleeve 40 present limiting shoulders which maintain the counterweight in its proper position within ythe case.

lVhat I claim is as follows:

1. In a mechanical level the combination with a. stock having a central cavity or bore on one side thereof; of a case adapted to lit Within the Cavity or bore and presenting an inner closed end or back plate, a face plate closing the outer end of the ease; means for securing the ease Within the eavity or bore; a fine arbor; means for rotatably mounting the arbor at one end in the face plate, and at its opposite end in the opposite end of the ease or back plate; a dial secured rigidly to the 'face plate; an index hand mounted rigidly on the protruding end of 'the arbor; a eounterweight; a goose neck connection for rigidly connecting the eounteiwveight to the arbor.

2. A mechanical level such as claimed in elaiin l the Counter-Weight or' which is conneeted te the arbor by a goose neck.

3. A, level such. as claimed in claim l the actuating; mechanism of which substantially Completely lills the oase between its ends and between the arbor and the side of the case sueh ease having' an opening to the atinosphere.

Il. A plumb level consisting of a stock having a Central cavity in one side thereof the outer end of the Cavity being` enlarged to present a shoulder; a hollow case mounted Within the cavity and having an open front, said ease having a peripheral flange surrounding` its open liront and bearing against the shoulder; means for securing' sai( vflange to 'the shoulder; a lace plate closing said open front of the ease; means 'for seeuringj the ifaee plate upon the case; a dial carried by the faee plate; an arbor liaving its ends journalled in the bael of the ease and the face plate, the 'liront end of the arbol` extending` through the `face plate and dial; a eounterweight connected to the arboi' Within the ease; an indicating device mounted upon the protruding' end of' the arbor and an outwardly flared protruding' plate secured upon the steek in position encircling the dial and concealing the surrounding portion of the ease.

In testimony whereo'll l. have signed my name to this specilieation.

ALFRED Y. HARPER. 

